On a turbo tune, you should never tweak the entire timing table "across the board" by a set amount. You should note that (depending on your engine and fuel type) there are certain timing amounts you should never exceed under boost. I particularly do not go beyond 15 degrees advance under boost with my setup in most ranges.
I'm always in learning mode finding new information and evaluating it, and opinions will vary. Spy and Greg, what are your opinions on this?
__________________
|